By some strange cosmic fluke, Kristen Stewart portrays a 16-year-old runaway in both of the movies in which she appears at this year’s Sundance Film Festival.

In the drama “Welcome to the Rileys,” which premiered Saturday afternoon at an industry-heavy screening at the Racquet Club Theater, the “New Moon Saga” superstar portrays someone quite unlike "Twilight's" long-suffering vampire-lover Bella Swan. That would be Mallory, a stripper-hooker with a penchant for wearing X-shaped pasties and G-strings (and sometimes no undies at all) with fishnet stockings who makes repeated references to the state of her “private parts” and sexual acts in language not suitable for publication in a family (or even PG-13-rated) blog.

Although her "Rileys" character initially claims to be 22, it is eventually revealed that Mallory ran away at an age when most teens are first getting a drivers license to live in semi-squalor in New Orleans, where she works in a French Quarter strip club in which she charges a little extra for more personal contact.

To get ready for the flesh- and soul-bearing part, the low-key Stewart -- dressed Saturday in the de facto Sundance regalia of military parka, distressed denim and sneakers -- said she didn’t “prep” per se, even though she studied some stripper dancing for the sake of greater realism.

“I’m not ‘playing a stripper’” she said with dripping emphasis before the film's first screening. “It’s really not a stripper movie at all. It sort of just opens your eyes about people that don’t have options. I know I’m speaking really vaguely about it.”

In the rock-surged comin- of-age drama “The Runaways,” Stewart portrays real-life rock icon Joan Jett, who co-founded the all-girl teenage band – yes, you guessed it – called the Runaways at age 16. The group burned brightly with righteous proto-punk fury then fizzled out between 1975 and ’79. In that film, Stewart snorts cocaine, makes out with co-star Dakota Fanning and drunkenly urinates on an electric guitar.

Did we mention that she embodies Jett almost perfectly?

“It’s, like, crazy,” Stewart said when a reporter asked her about her resemblance to one of rock’s foremost female titans. She bit her lip and ran her hand through her hair. “I can’t even accept it!”